Form for a concrete connection between a hot air pipe and a register in the floor ofa building



7 June 21, 1955 VAN WQRMER 2,711,001

FORM FOR A CONCRETE CONNECTION BETWEEN A HOT AIR PIPE AND A REGISTER IN THE FLOOR OF A BUILDING Filed D60. 20, 1952 A T TO lP/VE Y5 United States Patent FORM FOR A CONCRETE CONNECTION BE- TWEEN A HOT AIR PIPE AND A REGISTER IN THE FLOOR OF A BUILDING Donald K. Van Wormer, Slingerlands, N. Y.

Application December 20, 1952, Serial No. 327,086

3 Claims. (Cl. 25-118) My invention relates to forms for concrete air ducts and particularly to a form for molding a connection between a main air duct formed of laminated fiber which is to be buried in the floor of a building of the concrete slab-on-ground type, and a register in said floor.

At the present time, such forms are prefabricated of metal. While they do not weigh very much, they do occupy considerable space and the shipping and storage thereof is expensive.

Since the main air ducts in buildings of the above mentioned type are buried in the concrete floor of the building, the connections leading therefrom to the register in the floor are also buried in the concrete, the forms for the connections need not be made of metal, wood, or any other material of more or less permanent type because they are required to sustain the pressure of the concrete only for the comparatively short time between the pouring thereof and the initial set of the concrete. This being so, the forms for the connections may be made of paperboard, laminated paper or other material which is fairly stifi and yet flexible so that the form may be made and shipped flat in the nature of a developed pattern of the form which may be flexed and bent on the job and secured in bent or flexed condition to constitute the form for the connection.

One of the objects of my invention is to provide a form of the character described which can be shipped as a flat sheet thus effecting a great saving in shipping charges and a great saving in the space necessary for storage. A further object is to provide such a form which may be used to mold a connection running straight upwardly from the main air duct or which may be used to mold a connection having a portion which is angularly disposed to the vertical where the register is not vertically disposed above the main air duct.

I accomplish these objects by means of the novel element described below and illustrated in the accompanying drawing in which Fig. 1 is a plan view of the inner side of my form;

Fig. 2 is a section of Fig. 1 in the plane 22;

Fig. 3 is a section of Fig. l in the plane 3-3;

Fig. 4 is a vertical section through the concrete slab in which the main air duct is buried showing my form assembled and secured to the main air duct before the concrete is poured, and where the register in the floor is directly over the main air duct;

Fig. 5 is a side view of the main air duct with my form connected thereto, as shown in Fig. 4;

Fig. 6 is a vertical section through the concrete slab in which the main air duct is buried, showing my form connected thereto to mold a connection between the main air duct and a register in the floor where the register is offset to one side of the main air duct; and

Fig. 7 is a side view of the main air duct with my form connected thereto, as shown in Fig. 6.

Referring to the drawing and particularly to Figs. 1, 2 and 3, my form, as manufactured and shipped, is represented generally by the numeral 1 and comprises a flat, elongated, comparatively stiff but flexible sheet of fibrous material, such as stifi paperboard or laminated paper which may be impregnated or coated with paraflin or any other water proofing substance if necessary.

The width of the central portion of the form will depend upon the length of the register opening in the floor; the length of the straight marginal edges 2 and 3 will depend upon the diameter of the main air duct and also to a degree upon the width of the register opening in the floor and its distance above the main air duct. These factors or dimensions are largely standardized, at least where a group of similar dwellings are to be erected.

As illustrated, the length of the straight marginal edges 2 and 3 of the central portion of the form is somewhat in excess of one-half of the circumference of the outside of the main air duct 4. Extending longitudinally from each end of the central portion 5 which, for purposes of illustration, may be considered as extending between the points 6 and 7, are what I have termed side panels 8 and 9, the length of which is to be considered as extending from the point 6 to the score line it) and from the point 7 to the score line 11, respectively. The length of these side panels is such that,

when the form is wrapped around the main air duct, as

shown in Figs. 4 and 5, the side panels will be substantially tangent to the air duct and extend from the points of tangency to the level of the floor 12. At each side of the side panel 9 are the end-forming panels 13 and 14; and at each side of the side panel 8 are end-forming panels, each consisting of two parts 15 and 16, and 17 and 18, respectively. The side panel 8 may also be considered as consisting of two parts separated by the score line 8' which is aligned with the cuts 35 and 36, separating the portions 15 and 16, and 17 and 18, respectively, of the end panels which are attached to the side panel 8. The end edges 19 and 21 of the end-forming panels 16 and 18, respectively, which are opposed to the end edges 20 and 22 of the end-forming panels 13 and 14, respectively, are arcuate in shape and of a diameter equal to the diameter of the outside of the main air duct 4.

While the upper end of the form may be left open if care is exercised in pouring the concrete, I prefer to provide the side panel 8 with an end flap 23 provided with side tabs 24 and 25 and an end tab 26 which may be infolded along the score lines 27, 28 and 29, respectively, when the flap 23 is overfolded the opening in the top of the form in order to close the same, as shown in Figs. 4, 5, 6 and 7.

For reasons which will be later explained, I provide the side panel 9 with end flap 30 to which are attached side flaps 31 and 32 which may be infolded along the score lines 33 and 34, respectively.

When the register is directly above the main air pipe, as shown in Figs. 4 and 5, my form is assembled and attached to the air tube 4 by wrapping the central portion 5 thereof around the under side of the tube 4; infolding the end-forming panels 13 and 14 attached to the side-forming panel 9 and the end-forming panels 16, 17 and 18 attached to the side-forming panel 8. As illustrated in Fig. 4, the end panel-forming portion 18 is underfolded the end-forming panel portion 14 while the panel portion 17 is overfolded the end panel 14. When the central portion of the form has been wrapped around the air duct 4., it is secured thereto by means of staples 37, as shown in Fig. 5, and the panels 14, 17 and 18 are secured together by staples 38 and 39. The top closure flap 23 is folded over the top opening and may be secured in place by one of the staples 38, as shown in Fig. 4. When the form is used as in Fig. 4, the end flap 30 and the side flaps thereon 31 and 32 are cut off along the score line 11.

When the register opening is laterally ofliset from the main pipe or duct 4 as shown in Figs. 6 and 7, the side panel 8 is flexed along the score line 8' and the end flap 30 attached to the panel 9 is flexed, as shown in Fig. 6, along the score line 11. The end-forming panels are secured together by staples 40 and 41 and the side flaps 31 and 32 which are attached to the end flap 30 on side panel 9 are infolded, as shown in Fig. 6 and secured by the staples 42, and the flap 23 is folded over to close the opening in the top of the form. In this case, the edges 43 of the end-forming panels 15 and 17 will project slightly above the floor level and, if desired, may be cut off. It is to be understood, of course, that the form is secured to the main air pipe 4 by means of staples, such as shown at 44. Either before or after the concrete is poured, that portion of the main air duct 4 which extends upwardly between the points of tangency of the side panels 8 and 9, is cut out so that communication is provided between the main air duct and the register.

The dotted lines in Fig. 1 indicate score lines which are on or in the outer side of the form and which facilitate the folding of the various parts of the form along said lines.

I have described my invention in its preferred embodiment but it is to be understood that the words which I have used are words of description rather than of limitation and that changes, within the purview of the appended claims, may be made without departing from the true scope and spirit of my invention in its broader aspects.

What I claim is 1. A form adapted for molding a concrete connection between a hot air pipe and a register in the floor of a building having a foundation of the concrete slab-onground type in which said pipe is to be embedded; said form comprising a flat, elongated, comparatively stiff but flexible sheet of fibrous material having a central portion of a length at least substantially equal to onehalf the outer circumference of said pipe; side panels extending longitudinally from each end of said central portion each of a length adapted to extend upwardly from said central portion substantially to the level of said floor when said central portion is wrapped closely around said pipe; and end-forming panels at each side of each of said side panels of a width adapted, when bent at right angles to said side panels, to overlap the adjacent endforming panel on the other side panel; the opposed end edges of said end-forming panels being arcuate of a radius substantially equal to the radius of the outside of said pipe and substantially tangent to the lateral edges of said central portion at points common to said portion and said side panels; and said form having score lines therein between said side and end-forming panels to facilitate the bending of said end-forming panels at right angles to said side panels.

2. The structure set forth in claim 1 in which one of said side panels is provided with an end flap connected thereto along a transverse score line adapting it to be downwardly folded over the top of said form, when said form is in place, to form a closure for the top thereof.

3. A form adapted for molding a concrete connection between a hot air pipe and a register in the floor of a building having a foundation of the concrete slab-onground type in which said pipe is to be embedded; said form comprising a flat, elongated, comparatively stiff but flexible sheet of fibrous material having a central portion of a length at least substantially equal to onehalf the outer circumference of said pipe; side panels extending longitudinally from each end of said central portion each of a length adapted to extend upwardly from said central portion substantially to the level of said floor when said central portion is wrapped closely around said pipe; and end-forming panels at each side of each of said side panels of a width adapted, when bent at right angles to said side panels, to overlap the adjacent end-forming panel on the other side panel; one of said side panels comprising two connected portions having a transverse score line therebetween adapting said portions to be bent into angnlarly disposed relation, and having the end-forming panel at each side thereof comprising two portions separated by a cut extending outwardly from the ends of said score line; and the other of said side panels having an extension thereof provided with end-forming flaps; said extension being connected to said other side panel along a transverse score line, and each of said end-forming flaps being connected to said extension along a score line; the opposed end edges of said end-forming panels being arcuate of a radius substantially equal to the radius of the outside of said pipe and substantially tangent to the lateral edges of said central portion at points common to said portion and said side panels; and said form having score lines therein between said side and end-forming panels to facilitate the bending of said end-forming panels at right angles to said side panels.

References Cited in the file of this patent UNITED STATES PATENTS 1,721,442 Frink July 16, 1929 1,729,356 Murray Sept. 24, 1929 1,765,404 Cook June 24, 1930 1,821,951 Thompson Sept. 8, 1931 2,097,394 Fullman Oct. 26, 1937 

